As part of the massive mechanics revamp that came in patch 4.0.1, substantial changes have been made to the way damage over time spells are handled in Warcraft. The way you thought about DoTs in Wrath is now wrong; it’s time to start thinking of them the Cataclysm way.

Let’s take a look at the bread and butter DoT of Affliction: Corruption.

Setting aside abilities that refresh DoTs for a moment, in Wrath, the right way to refresh a DoT was to let it tick the last tick, then immediately refresh it, like so.

This gave you 12 ticks for 2 GCDs of work. Warlocks need to evaluate the DPCT (Damage Per Cast Time) of a spell, and in this case we see that those 2 GCDs gives us the full value of each Corruption spell (6 ticks) in the most amount of time.

What you wanted to avoid, at all costs, was clipping the DoT. Clipping your DoTs meant refreshing it before the last tick, like so:

Clipping the DoT overwrites the first cast entirely, so the final tick of the first one is cancelled out by the delay preceeding the first tick. In the time it took you to cast two Corruption spells, you got 11 ticks instead of 12. The DPCT of each Corruption has been lowered by 8% just because the DoT was clipped. That’s a huge DPS loss.

I like to think of it as a single unit, the pause first and then the tick. Casting the DoT starts with the pause, ignoring the previous spell.

This has been changed for the better in Cataclysm.

If you cast in between the penultimate and final ticks, your first Corruption spell gets its last tick in, and then the duration is extended beyond that as you’d expect. You don’t want to let it fall off, because then you’re introducing the lag we used to have, and you have about a 2 second window between ticks to refresh Corruption.

Why after the penultimate tick? Why not refresh it all the time?

Well, let’s see what happens then.

This example shows refreshing the DoT after the third tick. The fourth tick still happens – it doesn’t get clipped – but the duration doesn’t stack up to a full 36 seconds. You get 10 ticks for 2 GCDs of work, or a 17% DPCT loss for doing this early.

Now, this doesn’t mean you should NEVER do this. In a real fight, your instant casts should be refreshed whenever you’re moving, especially now that they don’t clip a tick in the middle of the rotation. If you’re moving, you should be casting your Curse, Bane, Corruption, and then Life Tap to keep up your mana. Never stop casting!

But standing still, yeah. Wait until the second to last tick, then refresh the DoT.

THE ONE DOT YOU STILL DON’T CLIP

The new refresh mechanics are fantastic, but there’s still one DoT you let fall off. Can you guess what it is?

Bane of Agony has quick (2 second) ticks that ramp up over the course of the DoT: 4 weak, 4 middle, 4 strong. This makes it ideal for use while pet tanking, as the aggro starts off very slow and ramps up with the damage.

But it also means that if you refresh the DoT before the final tick, you’ll overwrite a strong tick with a weak one.

This is somewhat counterintuitive, given how Corruption works above. You’d think that you’d get your strong tick off, and then 4 weak ticks. But no, you get 5 weak ticks. Strip off your gear and hit a training dummy, you’ll see it in the logs. Everything goes smoothly, you get 24 ticks total, but during the refresh you’ll get 5 weak ticks.

So. Let your Bane of Agony fall off, and refresh it once it does. Everything else? Hit before the last tick.

THE EFFECTS OF HASTE & HASTE PLATEAUS

Haste has changed so that it tries to fit more ticks in to a static spell duration, instead of reducing the duration with the same number of ticks. Each cast can give you more ticks of a spell than before. In Wrath, Haste could make an 18 second/6 tick Corruption spell a 13.5 second/6 tick spell, giving you a DPS increase without actually changing the DPCT of the DoT.

In Cataclysm, Haste adds more ticks into the existing duration, which maintains the same DPS, but increases the DPCT of each DoT. Let’s look at the two models.

Haste reduces the amount of time between ticks equally in both models, so the ticks are coming at the same frequency. Assuming spell damage has not been altered, then the DPS is exactly the same between each model.

What’s different is the DPCT of the DoT goes up dramatically in the Cataclysm model. Over a boss fight, you will spend less time refreshing the DoT if it adds ticks within the existing duration instead of shortening the duration. In a 5 minute fight, you’d spend 23 GCDs casting Corruption in Wrath, but only 17 GCDs in Cataclysm, for the exact same DPS. That’s a 35% increase in DPCT.

This means you have gained 6 GCDs to cast other spells during that fight, just by changing the way Haste is calculated. That’s pretty cool!

However, this new mechanic has created some interesting problems when stacking Haste.

See, the game now has to decide when it’s going to add another tick. There’s a specific amount of Haste which will give you a new tick, and when you hit that level of Haste, your DPS goes up by a large amount. But Haste only really benefits your DoTs when it gets you over the threshold. This rounding off leads to a phenomenon called the Haste Plateau.

Here’s the difference between 24% Haste and 25% Haste:

A very small amount of Haste in the first scenario would add a big DPS boost. Haste in the second situation doesn’t help very much (until you get near adding a 9th tick, of course.)

This is different from the Wrath method of simply compressing the DoT down – Haste scaled linearly with that model, with the more Haste added, the faster each DoT burned. In the Cataclysm model, Haste scales in a quantum fashion – you hit a threshold where the game rounds off, you get another tick. Then you plateau out until you reach the next threshold.

Here’s a graph, definitely not to scale, about how the different models worked.

This graph shouldn’t be taken as a DPS comparison between the two systems – it’s just a way to show the different kinds of scaling going on here. (Besides, DPS should be static between the two models.) But the idea is straightforward: there are Haste values where your DoT DPCT will take a big jump.

Now, you’re probably asking, what are those Haste values? When do I need to start looking to prioritize Haste over Mastery or Spellpower?

Well, for a Destruction Warlock using Immolate in a raid environment, Elitist Jerks has the Haste Plateau values as: 157, 781, 1406, 2030. My own testing shows that I don’t gain an extra Immolate tick until around 10% Haste, which I think was around 500 Haste. Not having raid buffs is probably the reason for the discrepancy in our two tests, so I’ll just put both out there and encourage you to hit the dummies with your own gear. Swap pieces in and out, reforge them, and then count the ticks on the dummy.

The most important thing to take away from this is that while Haste is, in general, very good for Warlocks (and other DoT-based caster classes), there are times that Haste will be better for you than others. Also, different spells will scale differently with different amounts of Haste due to duration and intervals between ticks. Bane of Doom (4 ticks every 60 seconds) scales poorly, while Bane of Agony (12 ticks every 24 seconds) scales really, really well. Immolate, Unstable Affliction (5 ticks over 15 seconds) and Corruption (6 ticks every 18 seconds) are all on the same 3-second scale.

There's a lot of math in this part, so Cynwise is going to reenact some of her favorite parts of The Return of the Jedi for you. You're welcome.

AUTOMATIC REFRESHES AND HASTE

All of the above is important theory for warlocks to know, but in practice, Affliction Warlocks never worry about refreshing Corruption manually. They keep it going with the Everlasting Affliction talent, which gives Haunt, Drain Life, and Drain Soul the ability to refresh it for them. This DoT-refreshing ability simplifies the Affliction priority list considerably, because all you have to worry about is keeping Haunt on the target, as it will take care of Corruption.

But, Affliction still needs to keep Unstable Affliction and Bane of Agony rolling on a target, and those now have two different methods they’ll need to consider.

Demonology has joined Affliction in the DoT-refreshing camp, as the new talent Cremation refreshes Immolate when Hand of Gul’dan is cast. This is cool, and helps reduce the complexity in an already complicated priority list. But the Cataclysm Haste model can do wonky things to this refresh.

Take a look at the 24% Haste example up above. See the dangling blue line at the end of it? That’s a good conceptual representation of what’s going on – you’ve got almost, but not quite, enough Haste to make it to that last tick. And the duration between the ticks is still really close.

But the DoT ends on the last tick. So while it’s convenient to say that Haste doesn’t reduce the duration of DoTs in the Cataclysm model, it’s not entirely accurate. But only Demonology warlocks refreshing Immolate with Hand of Gul’dan actually do need to worry about it right now. Pay attention, Demo locks!

I mentioned earlier that the game has a way to determine when you get another tick on your DoT. It takes the time between ticks – reduced by Haste – and divides the total duration of the DoT by that number. It then rounds off the result to figure out how many ticks you’ll have.

In other words:

Take the time between each tick – for Immolate, it’s 3 seconds.

Apply Haste to it by dividing it by 1 + the Haste percentage. For 9% Haste, it would be (3/1.09). 10% Haste would be (3/1.1).

Divide the total duration of the DoT by the hasted tick speed to find out how many ticks the DoT will have. Immolate is 15 seconds, so 10% Haste would be 15/(3/1.1) = 5.5 ticks. 9% Haste is 15/(3/1.09) = 5.45 ticks.

Round that number to the nearest integer, so 10% rounds to 6 ticks, while 9% rounds to 5.

So while you get 5 ticks at 9% Haste, and 6 ticks at 10% Haste, keep one important fact in mind: the tick speed is not rounded off. The spell ends when the last tick ticks.

DoT duration equals tick speed times number of ticks. So the following Haste values give you the following values:

At 9% Haste, each Immolate tick will take 2.7523 seconds. You’ll get 5 ticks, for a duration of 13.76 seconds.

At 10% Haste, each tick is 2.7273 seconds long. You get 6 ticks, for a duration of 16.3636 seconds.

At 15% Haste, ticks are 2.6087 seconds, you get 6 of them, and Immo lasts 15.65 seconds.

At 20% Haste, ticks are 2.5 seconds long, you get 6 of them, and Immo is exactly 15 seconds long again.

At 29% Haste, ticks are 2.32 seconds each, you have 6 of them, and Immo is 13.95 seconds long.

At 30% Haste, ticks are 2.3077 seconds long. This is the breakpoint for 7 ticks on Immo, and the DoT is 16.15 seconds long.

While this has interesting implications for Destruction (who should strive for 10% Haste no matter what), it is even more interesting implications for Demo.

Consider: Hand of Gul’dan is on a 12 second cooldown, with a 2 second cast time, before Haste. That’s 14 seconds between each refresh of a spell that, unhasted, has a 15 second duration. Okay, no problem, right?

Only, Haste can both shorten or lengthen the duration of Immolate, depending on the specific value. It never goes outside a certain range (13.64-16.36 seconds), but the lower end of that range drops below the CD and hasted cast time of Hand of Gul’dan.

Take 9% Haste again. 9% Haste brings HoG’s cast time down to (2/1.09) = 1.8349. With a 12 second CD, that means HoG can be cast once every 13.8349 seconds. Awesome!

Except you’re refreshing a spell that has a Hasted duration of 13.76 seconds. Oops.

There isn’t really a great solution for this, aside from Demonology locks knowing where their Haste is and making sure that they can effectively refresh Immolate. The area between 7-9.5% Haste seems to be the really dangerous area; the next such place where this happens is around 29% haste, and the HoG cast time is only 1.55 seconds then. So it’s not a big deal then, just at low Haste levels.

I don’t think the Cataclysm Haste mechanic is broken because of this issue. I think, if any technical solution is really needed, dropping the CD of HoG to 10 seconds through a Glyph would suffice.

This is just one of those places where the math gets really interesting, and where a little bit of Haste stacking can go a long way towards improving your DPS.

Did you have any idea DoTs could be so fascinating?

A FINAL WORD FOR HUNTERS (AND ROGUES AND FERAL DRUIDS AND…)

A final note about this article. While I’m writing this for Warlocks, these new rules should apply across the board to all magic DoTs. If you’re a caster with DoTs – Mage, Shadow Priest, Boomkin, Elemental Shaman, Warlock, and maybe even Death Knights, though I’m not positive – these rules should now apply to you. If you’re a class with physical damage DoTs, I’m 99% sure that Haste doesn’t affect your tick speed. You can also still clip your DoTs (if they don’t automatically refresh). The reasons behind it aren’t really clear to me, but I’ve been assured that this is how it works.

Basically, if your Haste is tied into your energy regeneration, you’re probably not getting any benefit to your DoTs from Haste. And that sucks.

Because this new way of handling DoTs? Sure, it requires some math to understand. But the changes are awesome.

I hope all DoTs start working like this soon.

Questions? Corrections? Leave ’em in the comments.

Update (January 11th, 2011): Somehow, I forgot to mention that I put together a calculator for Haste Sweet Spots. If you want to toy around with your own values, give it a try!

31 responses to “How Warlock DoTs Work in Cataclysm”

The stated reason that physical DoTs aren’t affected by Haste in the same way spell DoTs are, if I understood the Blue post correctly, is that those classes already benefit from Haste in terms of white damage(autoattacks) and resource regeneration. Allowing the DoTs to also benefit ran the risk of double dipping and possibly creating points where Haste becomes the Go To stat, even above Mastery or primary stats, kind of how ArPen worked out pre 4.0.1

Allowing the DoTs to also benefit ran the risk of double dipping and possibly creating points where Haste becomes the Go To stat, even above Mastery or primary stats, kind of how ArPen worked out pre 4.0.1

Which is a fat load of garbage, but considering GC posted it, who’s surprised?

Some of your examples are a little off. Not sure if it’s for simplification or not.

24% haste = 16.94 second dot with 7 ticks and a 1.20 second GCD
25% haste = 19.20 second dot with 8 ticks and a 1.19 second GCD

This means that at 24% Corruption gives 61.59 dps, 682 DPCT and at 25% 62.08 DPS & 993 DPCT. In other words, the importance of casting Corruption before another ability (based on DPCT) goes up, but the contribution of that 1% haste to the overall DPS is no different than going from 23% to 24% (61.09 to 61.59 is a 0.5 increase compared to the 0.49 for 24-25%. I’m rounding to 2dp so that will account for the 0.01 difference).

Yes, you are correct that 25% haste allows more time for spells to be cast between Corruption recasts, but this is essentially the reverse of the optimal haste value obsession that cropped up for Elemental at the start of WotLk with the 8 second Lava Burst cooldown. The question you have to ask is whether the 1% haste increase gives a larger DPS increase when comparing the overall DPS of the two rotation sets (ie: sure, you can cast more spells which means more damage, but there’s also more time so is it really a massive DPS increase?)

Or maybe I’m just over thinking things. I do that sometimes, and it’s also 1:30am here too >.<

Yeah, the 25/25 example is deliberately simplified. You caught me. 🙂 Haste is complex in that it affects three elements of casting at the same time, so I wanted to keep things simple while discussing the DPCT improvements. Like you said, DPS scales consistently with Haste no matter what. Holding the duration steady calls out why there are jumps and plateaus in your DPCT (and overall DPS).

This change is really important for Warlocks because it’s necessary for understanding why some DoTs have made their way back into rotations. Destro locks are used to ignoring Corruption, and it’s a little strange to have it be better DPCT than the 51, er, 31 point talent of the tree, Chaos Bolt. But the more Haste you stack to lower the cast time of your nukes, the better your DoT DPCT goes up. It’s a problem with the spec that folks will just have to get used to.

So what happened with Ele and Lava Burst? Were you having to optimize around a fixed CD?

Yeah, people were saying “you need 800 haste to get 5 Lbs in between LvB casts” and with some complicated math I went “nuh uh” (well, not really complicated, but I looked at dead time and LvB delays changing the DPCT for the last Lb).

“The question you have to ask is whether the 1% haste increase gives a larger DPS increase when comparing the overall DPS of the two rotation sets (ie: sure, you can cast more spells which means more damage, but there’s also more time so is it really a massive DPS increase?)” Quoting Binkenstein

I think this is an important point to maybe highlight more in your article. Perhaps I missed it, but what makes the haste plateau so especially worth it for the destruction warlock is not the extra tic for Immolate, but also the fact that the extra tic for Immolate increases the damage of Conflagerate. So both together are an overall DPS increase for that “rotation set”. This may not be the case for different “rotation sets” as Binkenstein tries to point out and need to be evaluated on a case by case basis.

Nice post. The graphics describing clipping are very clear as are the timelines to illustrate haste. However, your haste v. DPCT graph is a little misleading. As you describe in the text, the impact of haste in wrath had no effect on DPCT; it should be a flat line at the lowest step in this graph. The line you drew represents the DPS scaling in wrath instead. Of course the dps between the two mechanics is the same (again as stated in the text), which doesn’t make for an very interesting graph. The danger I see from this graph is an interpretation that haste gains between the steps have no benefit, when in fact, they raise dps in the same way they did previously. So, haste increases damage as linear ramp (dps) with large jumps at the break points (dpct).

Now I think your discussion of the variable timing on the rotation may dwarf the direct value of haste so all of this is pretty mute, but I’m a big fan of data visualization, so I thought I would point it out.

On a separate note, I was under the perhaps incorrect that cool downs scaled with haste as well, which would help maintain rotational stability. Does this vary between abilities, or is it never the case?

That’s a great point about the DPCT/Haste graph. I did that one originally as a DPS graph, but obviously it’s not. I’ll revise the graph and upload a new version. Some things I have to blame on this cold for just not thinking through – that graph has definitely been one of them!

I think the diagrams are actually very important here – this post is trying to make Haste accessible to players who don’t normally get into the math around a stat, and if the visualization is giving the wrong impression then I should change that. The only place where I’m deliberately fudging is on the static duration in the 24/25 example, just to make a point (ticks are pretty much the same, until you get another one in there.)

CDs aren’t scaling with Haste. If they did, it would definitely improve the Demo and Destro rotations, but would also make Haste the absolute most powerful stat you could get. Conflagrate would become even more of a monster spell if you could get it going every 7-8 seconds instead of 10. Glyphing it to 10 is already pretty huge.

It is worth noting that at least Ret pallies are getting talents to make certain rotational abilities (in the case of Ret Crusader Strike) have their CDs reduced by haste. Honestly I believe that Ret pallies are the only directly have the CDs reduced, whereas other classes have CDs reduced indirectly by haste.

Sadly I am at work and cannot access a talent tree, but elemental shaman have a talent called lava surge that gives flame shock DoT ticks a chance to reset the CD on lava burst. I am not 100% sure that haste affects flame shock’s ticks, but if it does then haste has an indrect affect on lavaburst’s CD. Demo warlocks may have one that works off of immolate to reduce Meta’s CD, but that talent has changed a few times and I am not sure what it is at this time.

In all seriousness, the reaction time required on some fights is pretty intense for max DPS or for good PvP play. But the Haste scaling up to 85 looks pretty steep, so I think the GCD softcap is going to be a lot tougher to reach.

This is all great and all, but at what point do we start playing a game instead of a spreadsheet or a gantt chart? I don’t have a stopwatch at my desk. With any amount of movement, doesn’t this become just entirely unwieldly?

Ok I know that to get extra ticks out of immolate with haste is 1406 and 2030, but here is my question. At 85 with casting fel flame giving you 6 extra sec on immotale, what are the haste numbers then? This is also quite an increase in dps to confag also. Fel flame is not in elitie jerks simcraft….not that I see.

One thing I’m wondering is, my haste constantly adjusts from 1204 to 1454 due to the Black Magic proc. This makes refreshing HoG easier especially with BM up. However, it’s guesswork when it comes to when to ‘clip’ corruption. The combat log in-game doesn’t seem to tell me the exact time things happen so I can’t work out dot intervals and test whether haste buffs are calculated on cast or per tick. So I’m struggling to know exactly when to clip corruption. I am using my scrolling combat text at the moment but it’s a little difficult to judge. If I can get some set values in my head of how much time left corruption should have without clipping it, with my haste level in mind, I can be confident I’m not clipping before the second to last tick, rather than after it.

So my question is, do tick intervals get recalculated every tick based on my current haste value, or on cast? If it’s on cast it will be considerably easier to know when to clip as I can work out my tick interval depending on my haste on cast. However, if it’s per tick, it will take some micro management to work out exactly when that second to last tick will occur, so I know when to clip.

They are recalculated every tick value, as far as I can tell. It’s either tick value or a dynamic value, but it’s definitely not a static value set at cast time. Watch the tooltip and hit a Haste trinket and you’ll watch the value drop as you hover over Corruption.

I just make a rule of thumb to refresh Corruption between 1-2 seconds left in NTK. Makes it easy enough.